Reading Material Exam 3 Flashcards
What is the distinction between altricial and precocial mammals during development? (p. 288)
altricial- immature and dependent at birth, undergo gradual transitions (birds and mammals)
precocial- rather mature at birth, emerge from embryonic stages as miniature adults (fish and reptiles)
- Be familiar with the section “Inhibition and Spontaneous Prenatal Behavior” (p. 296) In particular, the discussion of inhibitory control. Early researchers viewed the development of complex behavior from “reflexive” behaviors as a matter of inhibition of reflexes by supraspinal inhibition (i.e., inhibition from the nervous system above the spinal cord), or the coordination of relexes into more mature patterns of behavior. Instead, this section suggests that new neural
circuits (organization) emerge with development.
- the first thought was ruled out by pharmacological means which resulted in uncoordinated behavior
- instead of withdrawing or inhibiting preexisting circuits, the new belief is that new circuits are made during development
- in humans limb coordination comes early in gestation…
- human fetal activity is organized and activated by spinal and lower brain stem circuits…supraspinal mechanisms may play a more integrating role…inhibitory mechanisms are always playing a role but supraspinal mechanisms does not prevent premature expressions of postnatal patterns
- supraspinal mechanisms are above the spinal cord
- no gradual decrease in inhibition that can account for temporal pattern of emergence of postnatal behavior
. Read the section on “Feature of Neonatal Neurobehaivoral Organization.” Note how it is related to 3. (pp. 301-302). You might try to relate this discussion to compositional vs. interactional levels of organization. The old view is that neural organization is one of “recomposition” by means of inhibition of early reflexes. The newer view is one of reorganization of the nervous systems by establishing new interactions among nervous system
components.
- traditionally neonatal behavior heterogeneous and uncoordinated
- spontaneous behavior is patterned and coordinated
- neonates have different postures when supine prone seated or carried which affect interactions with caregiver
- not the same as reflexes and not just reflexes… that is nursing, rooting, etc reflexes are interdependent responses rather than independent reflexes and are coordinated and are not random
- eariler ideas of behavior dev- inhibition of reflexes
- neonatal behavior is patterned and represents organization and functioning patterns in the nervous system
- neural development is better described as integrated patterned reorganization rather than as the addition of layers over intact circuits
- prevalent neonate behavior- assymetrical posture- preferred direction of head orientation which influences limb movements
- example- when head turns toward sound arms and legs likely move too- these are not imcomplete or poorly controlled reaching reactions
- neonatal reflexes already work in functional systems, they aren’t independent components of a primitive nervous system that has to be orchestrated during development
- units of motor action are postures and movements not reflexes
- Role of descending control (pp. 303-304), especially note precision grasping in human infants.
- descending motor pathways are present at birth, but continue to expand in first year
- corticospinal pathway that creates the pyramidal tracts is the descending motor control system that exhibits the greatest postnatal development
- activity of a motor neuron is determined by the patterend relation of input from various pathways (spinal interneurons, brain stem fibers, etc)
- changes in behaviors of the infant don’t signal maturation of specific descending systems but mark developmental changes in the relative influence of each of the descending systems on spinal mechanisms
- complexity expands with development
Be familiar with the different types of physiological regulation in neonatal rats (pp. 317-323) What are adaptations and what are exaptations.
-prenatally: temperature, oxygen, water, electrolytes, nutrients via maternal blood supply and maternal regulation (1)
- postnatal mother, and other relatives
2) Milk
- when rat pups are isolated from mom their heart rate goes down and breathing decreases, because of a change in blood pressure
nursing- interaction between mom and pup- repeated microchanges in the pup’s physiology in response to milk ejections which may have lasting effects on the organisms physiology
3)Licking: Tactile Stimulation for pups that can’t defacte and urinate on their own yet, mom cleans them up too essentially recycling everything.
-licking and nuzzling is also important for growth, growth hormone decreases (found similarities for premature human babies, grew faster when massaged more)
-**quality, amount, intensity, and patterning of stimuli can influence a variety of developing systems
4) Temporal Sequences- within which systems become functional is important
ex: onset of visual functioning by premature exposure to light can alter organization of systems
Misc: Smaller animal the larger surface to volume ratio- lost heat faster
adult mammals are homeotherms (regulate own internal temperature)
-resemble ectotherms (young pups for example) by using behavioral means to collect heat from the environment- can move short distances to heat, litter, huddle- great metabolic savings (up to 40%)
-ultrasonic vocalizations (like in bats) first thought to be communicating distress, but may actually be initially an audible by product of phsyiological manuevers related to respiration and thermoregulation (constricts larynx)
Exaptation- something that developed for another function in the past but is used for what it wasn’t selected for later on ….
Adaptation- via natural selection…
What are the four contributions of developmental psychobiology to cognitive development? (pp. 334-335).
- new pscyhological achievements grow out of raw materials present at earlier phases of development, not constrained by functional categories
- recognition that the development of the nervous system is intimately dependent on contextual effects originating from both within and without the individual. (i.e., using the nervous system at earlier phases of development, brain and cognitive development are reciprocal and interdependent, behavior also contributes to the construction of the nervous system
- the individual is a part of a structured system that also includes the immediate social and physical surroundings…what is adaptive at one point may not be at another-ontogenetic adaptations. how does earlier competency relate to the development of later competency?
- since both internal and external elements to the system are important for its achievements, different combinations of internal and external can form similar-appearing achievements. For example, external support can be used to create the impression that infants have adult capacities when they don’t.
What are problems with two measures of cognitive maturation? (pp. 335-338).
1- one measure is nueral maturation and universality. If universality is thought to be found amidst different cultures, then it is presumed that other explanations like learning are not influential but this could be in err. universality of achievement could be a consequence of ubiquitous features of human extistence like adult care and offspring….
1- chronological aged, maturation is clocklike, often used as an independent variable. problems with this because development is more complex, different systems develop at different rates, which can affect the development of other systems, and also there is environmental influences
Other measures: myelination and electrophysiology (both also have issues
There are three views of the development of neurobehavioral elements that are taken as indices of maturation (pp. 342-344). What are these views, and what are some are some of their problems (e.g., p. 345)?
1) Age of Appearance- usually of specific motor acts or skills, nervous system is made up of independent parts so the different parts can mature at different times, for example specific sensorimotor abilities appear at different ages. extremely used as indicator of functional maturity, like performance of precision grasping might be used to indiciate maturation of the pathway connecting particular cells in the motor cortex to spinal cord that controls muscles in the hand.
2) Primitive Reflexes-disappearance of reflexes is an index of maturation of higher brain structures, which reappear in adults with damaged brain areas. inhibition IS a contributing factor to development but so is excitation! more likely that behavioral changes are due to both, not just inhibition. also studying damaged adult brains is not applicable to infants because their brains are organized diffrently.
3. Construction From Reflexes- neonate as a bundle of reflexes considered to be building blocks for more complex. Example: taking a toy from a box depends on orchestration of reflexes of the motor cortex and spinal cord by structures in the frontal lobe.
- phases in development are adaptations to current conditions and not solely as preparations for later
- above 3 ideas are incorrectly based on two theories: 1) development is gradual and continous as child takes on more features of an adult
How does the brain change in complex environments? (p. 356)
-dendritic growth and synaptogenesis occur in complex environments may be result of learning that occurs during exploratory behavior of animals. growth can’t be explained by a nonspecific effect like growth or stress. glia and capillaries also increase in regions with dendritic plasticity
rats trained in acrobatic tasks that exercies and learn new motor skills increase in both capillaries (seen with only exercise) and number of sysnapses
What are the two contrasting view of intelligence during infancy? (p. 358)
- in one infants are thought to be adults but less complete, new abilities explained by maturation of already existing systems
- Piaget: sensorimotor intelligence, infancy is foundation for intelligence in later stages, qualitative differences of intelligence in infancy and later stages
Why might not brain damaged adults provide insights into the development of the nervous system in infants? (pp. 363-364)
nervous system of an infant is organized and adaptive, not an incomplete version, movement is orchestrated, and an infant (sometimes an adult) has not worked out the timing yet
What are the two orientations towards animal behavior as described in the textbook? (pp. 383-386). Consider the advantages and disadvantages of both.
1) natural history- behavioral patterns that enable animals to cope with environment, behavior is related to evolution and ecological processes, animal and its world and differences between animals and humans
2)anthropocentric orientations- behavior of animals for two reason- a) define an examine laws of behavior that apply generally to all animals- to apply to humans. B) considered good model of certain aspects of human functioning. understanding animals is a secondary motive.
Ex: achromatopsia (loss of ability to see color) though same area associated in macaques, lesions did not produce expected results
. What is Human Ethology? What are some of its questions and problems with the approach?(pp. 390-392)
-a species must be studied as a separate entity having its own properties, can’t overlap species, so humans would need to be directly studied at some point.
-identify human behaviors that are universal, sophisticated descriptions in typical human settings, which have presumed to evolved as adaptations to selective pressures. Difficulties are distinguishing between the unnatural and natural setting in humans. This has led to some researchers looking at human behaviors in nomadic groups assuming they are like earlier humans.
-people who look at universalities… can’t assume that it is the difference between learned and innate behavior.
blurred with social sciences
Be familiar with how Michel and Moore suggest that ethnological methods can be applied to human development. (pp. 392-403)
Description/observation, problems with using abstract categories in language to describe things, may infer what really is not there, so use interobserver reliability, thus ethologists use objective terms
-recordings- film, aduio, etc (though not always practical)
Know the terms latency, frequency, duration, and intensity as they apply to patterns of behavior (pp. 395-396).
latency-how much time elapses after some event of interest before the behavior occurs
frequency-how often the behavior occurs in some unit of time
duration- how long a particular pattern of behavior lasts
intensity-amplitude, often judged without reference to time
